Amino acid alterations in Gag that confer the ability to grow in simian cells on HIV-1 are located at a narrow CA region

We previously generated a prototype monkey-tropic human immunodeficiency virus type 1 (HIV-1) designated NL-DT5R. This viral clone has a small region of simian immunodeficiency virus (SIV) within Gag capsid (CA) protein and also SIV Vif protein, but displays a poor growth phenotype in simian cells. To improve the growth potential of NL-DT5R, we have constructed a series of its gag variant viruses. Out of fourteen viral clones generated, five were infectious for simian HSC-F cells, and two of the infectious variants grew similarly with NL-DT5R. Taking their genome structures into consideration, our data here clearly show that a narrow CA region within the Gag protein, i.e., the domain around cyclophilin A (CypA)-binding loop, is critical for the growth ability of HIV-1 in simian cells

Different interaction between HIV-1 Vif and its cellular target proteins APOBEC3G/APOBEC3F

We examined a series of site-directed point mutants of human immunodeficiency virus type 1 (HIV-1) Vif for their interaction with cellular anti-viral factors APOBEC3G/APOBEC3F. Mutant viruses that display growth-defect in H9 cells did not counteract effectively APOBEC3G and/or APOBEC3F without exception, as monitored by single-cycle infectivity assays. While growth-defective mutants of Vif C-terminal region were unable to suppress APOBEC3G/APOBEC3F, some N-terminal region mutants did neutralize one of APOBEC3G/APOBEC3F. These data have suggested that members of APOBEC3 family other than APOBEC3G/APOBEC3F are not important for anti-HIV-1 activity. Furthermore, APOPEC3G/APOBEC3F were found to differently associate with Vif in virions as analyzed by equilibrium density centrifugation. Taken together, these results indicated that interaction of HIV-1 Vif and APOBEC3G is distinct from that between Vif and APOBEC3F

Realization of Strategic Analysis of Manutan s.r.o. Company

Import 22/07/2015V této práci je popsána strategická analýza firmy Manutan s. r. o. Teoretická část obsahuje vymezení základních pojmů a analýz. Praktická část je zaměřená na aplikaci analýz, vymezení závěru a doporučení pro analyzovanou firmu.In this work is described strategic analysis of the company Manutan s.r.o. The theoretical part defines the basic concepts and analysis. The practical part is devoted to the application of analysis, definition of conclusions and recommendations for the analyzed company.115 - Katedra managementuvýborn

The Human Gut Microbe <i>Bacteroides thetaiotaomicron</i> Suppresses Toxin Release from <i>Clostridium difficile</i> by Inhibiting Autolysis

Disruption of the human gut microbiota by antibiotics can lead to Clostridium difficile (CD)-associated diarrhea. CD overgrowth and elevated CD toxins result in gut inflammation. Herein, we report that a gut symbiont, Bacteroides thetaiotaomicron (BT), suppressed CD toxin production. The suppressive components are present in BT culture supernatant and are both heat- and proteinase K-resistant. Transposon-based mutagenesis indicated that the polysaccharide metabolism of BT is involved in the inhibitory effect. Among the genes identified, we focus on the methylerythritol 4-phosphate pathway gene gcpE, which supplies the isoprenoid backbone to produce the undecaprenyl phosphate lipid carrier that transports oligosaccharides across the membrane. Polysaccharide fractions prepared from the BT culture suppressed CD toxin production in vitro; the inhibitory effect of polysaccharide fractions was reduced in the gcpE mutant (ΔgcpE). The inhibitory effect of BT-derived polysaccharide fraction was abrogated by lysozyme treatment, indicating that cellwall-associated glycans are attributable to the inhibitory effect. BT-derived polysaccharide fraction did not affect CD toxin gene expression or intracellular toxin levels. An autolysis assay showed that CD cell autolysis was suppressed by BT-derived polysaccharide fraction, but the effect was reduced with that of ΔgcpE. These results indicate that cell wall-associated glycans of BT suppress CD toxin release by inhibiting cell autolysis

The Human Gut Microbe Bacteroides thetaiotaomicron Suppresses Toxin Release from Clostridium difficile by Inhibiting Autolysis

Disruption of the human gut microbiota by antibiotics can lead to Clostridium difficile (CD)-associated diarrhea. CD overgrowth and elevated CD toxins result in gut inflammation. Herein, we report that a gut symbiont, Bacteroides thetaiotaomicron (BT), suppressed CD toxin production. The suppressive components are present in BT culture supernatant and are both heat- and proteinase K-resistant. Transposon-based mutagenesis indicated that the polysaccharide metabolism of BT is involved in the inhibitory effect. Among the genes identified, we focus on the methylerythritol 4-phosphate pathway gene gcpE, which supplies the isoprenoid backbone to produce the undecaprenyl phosphate lipid carrier that transports oligosaccharides across the membrane. Polysaccharide fractions prepared from the BT culture suppressed CD toxin production in vitro; the inhibitory effect of polysaccharide fractions was reduced in the gcpE mutant (ΔgcpE). The inhibitory effect of BT-derived polysaccharide fraction was abrogated by lysozyme treatment, indicating that cellwall-associated glycans are attributable to the inhibitory effect. BT-derived polysaccharide fraction did not affect CD toxin gene expression or intracellular toxin levels. An autolysis assay showed that CD cell autolysis was suppressed by BT-derived polysaccharide fraction, but the effect was reduced with that of ΔgcpE. These results indicate that cell wall-associated glycans of BT suppress CD toxin release by inhibiting cell autolysis

Microbicidal effects of weakly acidified chlorous acid water against feline calicivirus and Clostridium difficile spores under protein-rich conditions.

Sanitation of environmental surfaces with chlorine based-disinfectants is a principal measure to control outbreaks of norovirus or Clostridium difficile. The microbicidal activity of chlorine-based disinfectants depends on the free available chlorine (FAC), but their oxidative potential is rapidly eliminated by organic matter. In this study, the microbicidal activities of weakly acidified chlorous acid water (WACAW) and sodium hypochlorite solution (NaClO) against feline calcivirus (FCV) and C. difficile spores were compared in protein-rich conditions. WACAW inactivated FCV and C. difficile spores better than NaClO under all experimental conditions used in this study. WACAW above 100 ppm FAC decreased FCV >4 log10 within 30 sec in the presence of 0.5% each of bovine serum albumin (BSA), polypeptone or meat extract. Even in the presence of 5% BSA, WACAW at 600 ppm FAC reduced FCV >4 log10 within 30 sec. Polypeptone inhibited the virucidal activity of WACAW against FCV more so than BSA or meat extract. WACAW at 200 ppm FAC decreased C. difficile spores >3 log10 within 1 min in the presence of 0.5% polypeptone. The microbicidal activity of NaClO was extensively diminished in the presence of organic matter. WACAW recovered its FAC to the initial level after partial neutralization by sodium thiosulfate, while no restoration of the FAC was observed in NaClO. These results indicate that WACAW is relatively stable under organic matter-rich conditions and therefore may be useful for treating environmental surfaces contaminated by human excretions

Effect of BSA on FCV inactivation by WACAW and NaClO.

<p>The virucidal activity against FCV F9 was examined without BSA (A) or with 0.5% (w/v) BSA (B) or 5.0% (w/v) BSA (C). The remaining FCV infectivity after treatment with the test sanitizers for the indicated times was quantified by plaque assay. Data are expressed as means ± standard deviations obtained from three independent experiments. * Significantly different from the data in NaClO with 25 ppm (A), 200 ppm (B) and 3,000 ppm (C) at each time point (<i>p</i> <0.01).</p